Field of the Invention
The invention relates to a channel structure, and more particularly, relates to a vertical channel structure.
Description of Related Art
With continuous development of technologies, advancements in electronic devices lead to increasing demands for greater storage capabilities. In order to satisfy the need for high storage density, memory devices are designed to include smaller size and higher integration. Accordingly, a structure of the memory device has been developed to change from a 2D memory device with a planar gate structure into a 3D memory device with a vertical channel (VC) structure.
During a manufacturing process of the 3D memory device with the vertical channel structure, because a high aspect ratio of a VC hole will reduce a capability of a dielectric material for filling the VC hole, a void is easily formed in the dielectric material filled in the VC hole.
In the subsequent process of forming a plug for channel pick up, a conductive material for forming the plug often passes through the dielectric material to enter the void. As a result, an undesired potential may be generated to lower performance of the memory device.